1. Field of the Invention
The present general inventive concept relates to an ink-jet head mount and an ink-jet printing apparatus using the same, and more particularly to an ink-jet head mount to minutely adjust a position of an ink-jet head to eject red ink, green ink, and blue ink on a glass panel in an ink-jet printing system to manufacture a color filter for a liquid crystal display (LCD).
2. Description of the Related Art
An ink-jet printing method is used to manufacture a color filter used in thin film transistor-liquid crystal displays (TFT-LCD). A glass panel having a pixel matrix to form the color filter is printed on by a piezo-driven ink-jet head having a plurality of nozzles to eject the ink onto the pixel matrix. The ink on the pixel matrix is then hardened to form a color filter layer. In comparison to conventional photolithography methods, this ink-jet printing method can remarkably reduce materials used in manufacturing the color filter and can reduce a number of processing steps.
Conventional ink-jet printing apparatuses used in the ink-jet printing method are disclosed in U.S. Pat. No. 6,565,206 and Japanese Patent Laid-Open No. 2003-048312. U.S. Pat. No. 6,565,206, discloses an ink-jet printing apparatus including a single head unit in which three ink-jet heads for red color, green color, and blue color are provided. Each ink-jet head is installed to rotate in a θ direction and to linearly move in a B-direction. In other words, each ink-jet head is installed to move with two-degrees-of-freedom. As such, positions of the ink-jet heads are adjusted to arrange the ink-jet heads on the pixel matrix. Japanese Patent Laid-Open No. 2003-048312 discloses an ink-jet printing apparatus including a plurality of ink-jet heads, wherein each ink-jet head is installed to perform the two-degree-of-freedom movement in a single directional rotating movement and a single directional linear motion.
In an ink-jet printing apparatus for manufacturing a color filter using three color ink-jet heads, that is, red (R), green (G), and blue (B) color ink-jet heads, a device for minutely adjusting respective ink-jet heads is required to equalize a nozzle pitch NP between nozzles formed in lower surfaces of respective ink-jet heads with a pixel pitch PP between lattices on the pixel matrix.
When a high resolution pixel matrix is used (generally, less than a few μm), it is more difficult to precisely adjust the nozzle pitch NP, the pixel pitch PP, and positions of the ink-jet heads. As a result, ink ejected from the ink-jet heads may not be precisely coated within a desired pixel cavity of the pixel matrix for the color filter and some portion thereof may be coated outside of the desired pixel cavity. This may lead to an increase in a number of inferior color filters manufactured.
Glass panels of the TFT-LCD are manufactured in a variety of models according to user demand, and the pixel pitch PP is different according to the various models. Thus, the ink-jet heads must be arranged to correspond to the pixel pitch PP of respective models. In the conventional ink-jet printing apparatuses, since the respective ink-jet heads rotate and linearly move, the positions of the heads can be adjusted according to the pixel pitch PP of the glass panels used to manufacture the color filter.
However, the conventional ink-jet heads move according to only two-degrees-of-freedom, so that there is a limit to the precision with which the position of the ink jet heads may be adjusted.
Moreover, since the positions of the conventional ink-jet heads are minutely adjusted by a plurality of mechanical components, driving errors, such as friction between the mechanical components, backlash, pitching, yawing, rolling, or the like, are inevitable, so that the positions of the ink-jet heads cannot be precisely adjusted.